Licensing, in terms of licensing software for example, can be offered in many different ways. These include but are not limited to restricted pay-per-use licenses and licenses without time restriction or without restriction on the number of uses. One problem with unlimited licenses is that many potential clients may avoid taking the license if the licensing fees for such a license, unrestricted by use or time, are too high. If the potential client could pay only for the uses of the license, which can hopefully be passed on to another party, then the potential client may become more interested in licensing the software.
One way of licensing software on a pay-per-use basis is disclosed in U.S. Pat. No. 6,049,789. In such a system, however, each licensee makes contact with the licensor at regular intervals, to pay for each use of the license. Such periodic contact, however, is not always possible.
Flexlm from Macrovision is another software licensing system. In this type of system, calls to the license system are spread over the parts of the code that needs to be licensed. Each call supplies the name of the licensed feature (e.g. FILMING, VIEWER, . . . ) and a version as a parameter. The vendor also supplies a driver to retrieve machine identification safely and to provide this to the licensing system.
The end user then installs a license file on his machine, that he purchased from the vendor. This file contains for each licensed feature information about name, expiration date, and an encrypted license key for example. The system checks the license file and the license is granted. If not, an error is returned. All such systems, however, involve a constant or periodic contact link with the vendor and/or do not involve pre-paid licenses.
With such known licensing systems, contact with the licensor is necessary to pay for a number of uses, monitor uses, attribute particular licenses to particular machines, etc. This can be a problem, especially in the area of licensing software for machines, such as medical devices for example, wherein maintaining a constant or periodic contact link between the licensee and licensor is impossible or at least extremely difficult.
Another way to pay for uses of a product, for example, can be found in the mobile communication field. Here, it is easy for the owner to make periodic contact with the purchaser. Pre-payment can occur by selling a prepaid card, wherein with each use, a contact to the owner is first made. While this is a way to pay for uses of a product, it is not readily applicable to software licenses.